Milk carton makes great place for seeds
Dear Helen: I have heard that you construct seeding flats from milk cartons. Please explain how to do this. I’d also appreciate some tips on the indoor seeding process.
ANSWER: Two-litre milk and juice cartons with a side removed have an ideal depth for seeding and growing most flowers and vegetables into transplant size in the same container.
To turn a carton into a seeding flat, cut out the side with the pouring spout, trim the removed side to remove the upper, pouring part, and wash the side and the opened carton in hot, soapy water. Let them air dry. Place the removed part inside the carton so that it curves up against the top and part way along the two sides. Staple it in place. This closes off the partly opened end and prevents soil from drifting out. Use scissors or a knife to punch three drainage holds in the bottom.
For just a few lettuce, broccoli or cabbage plants, I use one-litre cartons or small plastic flats I have purchased plants in. The plastic flats can be washed and used from year to year.
To seed, fill the containers to within 12 mm of the tops with gently firmeddown mix. Press well into the corners, where the mix will tend to sink. Moisten the soil mix in the filled flats. I use a hot, diluted seaweed fertilizer solution, which contains hormones and nutrients that aid germination and initial root growth. Keep the solution weak, though, at less-than-recommended label rates.
Pour seeds into the dry palm of one hand, and take out small pinches to disperse sparingly over the moistened soil surface between thumb and forefinger of the other hand. Give the seeds a scant covering of mix, pressed down gently and spray-misted to dampen. Cover the seeded containers loosely with plastic. Most seeds germinate well at room temperature. Thin the seedlings as needed as they develop in bright indirect light and coolish room temperatures.
Two-litre milk cartons with the tops cut off are useful also for the last stages of tomato transplant development. Deleafed stems immersed in a carton’s length develop roots all along the stem, for an extensive root system at the time of outdoor transplanting.
— Canwest News Service